U.S. patent application number 16/977407 was filed with the patent office on 2021-02-11 for reactor.
The applicant listed for this patent is AutoNetworks Technologies, Ltd., Sumitomo Electric Industries, Ltd., Sumitomo Wiring Systems, Ltd.. Invention is credited to Shinichiro Yamamoto, Kohei Yoshikawa.
Application Number | 20210043368 16/977407 |
Document ID | / |
Family ID | 1000005195629 |
Filed Date | 2021-02-11 |
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United States Patent
Application |
20210043368 |
Kind Code |
A1 |
Yamamoto; Shinichiro ; et
al. |
February 11, 2021 |
REACTOR
Abstract
A reactor includes: a coil; a magnetic core arranged inside of
the wound portion and an outer core portion arranged outside of the
wound portion; and a resin molded portion. An interval between the
wound portion and the inner core portion differs in a peripheral
direction of the wound portion. The reactor includes an
electrically insulating material that is interposed in a location
at which the interval is the narrowest, and a thick portion that is
interposed in a location at which the interval is the widest and
forms a portion of the inner resin portion. The proportion of the
interval of the narrowest location with respect to the thermal
conductivity is less than the proportion of the interval with
respect to the thermal conductivity.
Inventors: |
Yamamoto; Shinichiro;
(Yokkaichi-shi, Mie, JP) ; Yoshikawa; Kohei;
(Yokkaichi-shi, Mie, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AutoNetworks Technologies, Ltd.
Sumitomo Wiring Systems, Ltd.
Sumitomo Electric Industries, Ltd. |
Yokkaichi-shi, Mie
Yokkaichi-shi, Mie
Osaka-shi, Osaka |
|
JP
JP
JP |
|
|
Family ID: |
1000005195629 |
Appl. No.: |
16/977407 |
Filed: |
February 19, 2019 |
PCT Filed: |
February 19, 2019 |
PCT NO: |
PCT/JP2019/006109 |
371 Date: |
September 1, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01F 27/306 20130101;
H01F 27/255 20130101; H01F 27/324 20130101 |
International
Class: |
H01F 27/30 20060101
H01F027/30; H01F 27/255 20060101 H01F027/255; H01F 27/32 20060101
H01F027/32 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 5, 2018 |
JP |
2018-039159 |
Sep 20, 2018 |
JP |
2018-175975 |
Claims
1. A reactor comprising: a coil having a wound portion; a magnetic
core that includes an inner core portion arranged inside of the
wound portion and an outer core portion arranged outside of the
wound portion; and a resin molded portion including an inner resin
portion that fills at least a portion between the wound portion and
the inner core portion and an outer resin portion that covers at
least a portion of the outer core portion, wherein an interval
between the wound portion and the inner core portion differs in a
peripheral direction of the wound portion, the reactor includes an
electrically insulating material that is interposed in a location
at which the interval is the narrowest, and a thick portion that is
interposed in a location at which the interval is the widest and
forms a portion of the inner resin portion, and letting a thermal
conductivity of the electrically insulating material be .lamda.1,
the interval of the narrowest location be t1, and the proportion of
the interval t1 with respect to the thermal conductivity .lamda.1
be (interval t1/thermal conductivity .lamda.1), and letting a
thermal conductivity of the electrically insulating material be
.lamda.2, the interval of the widest location be t2, and the
proportion of the interval t2 with respect to the thermal
conductivity .lamda.2 be (interval t2/thermal conductivity
.lamda.2), (interval t1/thermal conductivity .lamda.1)<(interval
t2/thermal conductivity .lamda.2) is satisfied.
2. The reactor according to claim 1, wherein the reactor includes a
thin portion that is interposed in at least a portion of the
location at which the interval between the wound portion and the
inner core portion is relatively narrow, the thin portion forming
another portion of the inner resin portion.
3. The reactor according to claim 2, wherein the electrically
insulating material and the thin portion are included at the
location at which the interval between the wound portion and the
inner core portion is relatively narrow.
4. The reactor according to claim 1, wherein the interval t1 of the
narrowest location is 50% or less of the interval t2 of the widest
location.
5. The reactor according to claim 1, wherein the wound portion has
a quadrangular tube shape and the inner core portion has a
quadrangular column shape, and the location at which the interval
between the wound portion and the inner core portion is relatively
narrow includes a flat plate-shaped location that is interposed
between a surface of an inner peripheral surface of the wound
portion and a surface of an outer peripheral surface of the inner
core portion.
6. The reactor according to claim 1, wherein the thermal
conductivity .lamda.1 of the electrically insulating material is
higher than the thermal conductivity .lamda.2 of the thick
portion.
7. The reactor according to claim 1, wherein the electrically
insulating material includes at least one of insulating paper and
insulating film.
8. The reactor according to claim 1, wherein the electrically
insulating material includes a molded body including a resin that
is the same as a constituent resin of the inner resin portion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. national stage of
PCT/JP2019/006109 filed on Feb. 19, 2019, which claims priority of
Japanese Patent Application No. JP 2018-039159 filed on Mar. 5,
2018 and Japanese Patent Application No. 2018-175975 filed on Sep.
20, 2018, the entire contents of which are incorporated herein by
reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a reactor.
BACKGROUND
[0003] JP 2017-135334A discloses, as a reactor to be used in an
in-vehicle converter or the like, a reactor that includes a coil
including a pair of wound portions, a magnetic core that is
arranged inside and outside of the wound portions, and a resin
molded portion that covers the outer periphery of the magnetic
core. The above-described magnetic core includes multiple core
pieces that are assembled in a ring shape. The above-described
resin molded portion exposes the coil without covering it.
[0004] Further improvement of a heat dissipation property is
desired in a reactor. If a coil is exposed from a resin molded
portion as described above, the wound portion of the coil can come
into direct contact with a liquid refrigerant or wind from a fan,
for example. This kind of reactor has an excellent heat dissipation
property. Also, if the installation target to which the reactor is
attached includes a cooling mechanism, or a cooling mechanism is
provided independently of the installation target in the
surrounding area of the location in which the reactor is installed,
the wound portion of the coil can be brought close to the
installation target or the cooling mechanism. This kind of reactor
has an excellent heat dissipation property. However, a reactor with
a more excellent heat dissipation property is desired due to
reasons such as an increase in the temperature of the coil and the
magnetic core accompanying an increase in current, and a reduction
of the heat dissipation area accompanying a reduction of the size
of the reactor.
SUMMARY
[0005] A reactor of the present disclosure includes a coil having a
wound portion; a magnetic core that includes an inner core portion
arranged inside of the wound portion and an outer core portion
arranged outside of the wound portion; and a resin molded portion
including an inner resin portion that fills at least a portion
between the wound portion and the inner core portion and an outer
resin portion that covers at least a portion of the outer core
portion, in which an interval between the wound portion and the
inner core portion differs in a peripheral direction of the wound
portion. The reactor includes an electrically insulating material
that is interposed in a location at which the interval is the
narrowest, and a thick portion that is interposed in a location at
which the interval is the widest and forms a portion of the inner
resin portion, and letting a thermal conductivity of the
electrically insulating material be .lamda.1, the interval of the
narrowest location be t1, and the proportion of the interval t1
with respect to the thermal conductivity .lamda.1 be (interval
t1/thermal conductivity .lamda.1), and letting a thermal
conductivity of the electrically insulating material be .lamda.2,
the interval of the widest location be t2, and the proportion of
the interval t2 with respect to the thermal conductivity .lamda.2
be (interval t2/thermal conductivity .lamda.2), (interval
t1/thermal conductivity .lamda.1)<(interval t2/thermal
conductivity .lamda.2) is satisfied.
Effect of the Present Disclosure
[0006] The reactor of the present disclosure has an excellent heat
dissipation property.
BRIEF DESCRIPTION OF DRAWINGS
[0007] FIG. 1 is a schematic perspective view showing a reactor
according to a first embodiment.
[0008] FIG. 2A is a cross-sectional view obtained by cutting the
reactor of the first embodiment along a cutting line (II)-(II)
shown in FIG. 1.
[0009] FIG. 2B is a diagram illustrating an interval between a
wound portion and an inner core portion in the reactor shown in
FIG. 2A.
[0010] FIG. 3 is an exploded perspective view showing a combined
body included in the reactor according to the first embodiment.
[0011] FIG. 4A is a cross-sectional view obtained by cutting a
reactor according to a second embodiment with a plane orthogonal to
an axial direction of a wound portion.
[0012] FIG. 4B is a diagram illustrating an interval between a
wound portion and an inner core portion in the reactor shown in
FIG. 4A.
[0013] FIG. 5 is a cross-sectional view obtained by cutting a
reactor according to a third embodiment with a plane orthogonal to
an axial direction of a wound portion.
DISCLOSURE
Detailed Description of Preferred Embodiments
[0014] First, embodiments of the present disclosure will be listed
and described.
[0015] A reactor of the present disclosure includes a coil having a
wound portion; a magnetic core that includes an inner core portion
arranged inside of the wound portion and an outer core portion
arranged outside of the wound portion; and a resin molded portion
including an inner resin portion that fills at least a portion
between the wound portion and the inner core portion and an outer
resin portion that covers at least a portion of the outer core
portion, in which an interval between the wound portion and the
inner core portion differs in a peripheral direction of the wound
portion. The reactor includes an electrically insulating material
that is interposed in a location at which the interval is the
narrowest, and a thick portion that is interposed in a location at
which the interval is the widest and forms a portion of the inner
resin portion, and letting a thermal conductivity of the
electrically insulating material be .lamda.1, the interval of the
narrowest location be t1, and the proportion of the interval t1
with respect to the thermal conductivity .lamda.1 be (interval
t1/thermal conductivity .lamda.1), and letting a thermal
conductivity of the electrically insulating material be .lamda.2,
the interval of the widest location be t2, and the proportion of
the interval t2 with respect to the thermal conductivity .lamda.2
be (interval t2/thermal conductivity .lamda.2), (interval
t1/thermal conductivity .lamda.1)<(interval t2/thermal
conductivity .lamda.2) is satisfied.
[0016] The reactor of the present disclosure has an excellent heat
dissipation property due to the following reasons.
[0017] The outer peripheral surface of the wound portion of the
coil is exposed and is substantially not covered by the resin
molded portion. For this reason, for example, the wound portion can
come into direct contact with a liquid refrigerant or air from a
fan. In addition, the wound portion can be brought close to the
cooling mechanism or to the installation target including the
cooling mechanism. This kind of reactor of the present disclosure
has an excellent heat dissipation efficiency.
[0018] There is a relatively narrow location between the wound
portion of the coil and the inner core portion of the magnetic
core.
[0019] It can be said that if at least a portion of the relatively
narrow location is provided at a location corresponding to the
following heat dissipation location on the outer peripheral surface
of the wound portion, the distance from the inner core portion to
the heat dissipation location of the wound portion is short. This
kind of reactor of the present disclosure can efficiently dissipate
heat from the inner core portion to the wound portion. Examples of
the heat dissipation location of the wound portion include a
location with which a fluid coolant such as the above-described
liquid refrigerant can come into direct contact, and a location
that is arranged near the above-described installation target or
the cooling mechanism in the wound portion.
[0020] The reactor of the present disclosure satisfies a
predetermined condition that (interval t1/heat dissipation rate
.lamda.1) is smaller than (interval t2/heat dissipation rate
.lamda.2) regarding the heat dissipation rate of an interposing
member that is present between the wound portion and the inner core
portion, and the interval of the location at which the interposed
member is arranged.
[0021] For example, if the constituent material of the electrically
insulating material and the constituent material of the thick
portion are the same, the thermal conductivities .lamda.1 and
.lamda.2 are substantially equal. However, the interval t1 is
smaller than the interval t2. That is, due to the distance from the
inner core portion to the heat dissipation surface of the wound
portion being short as described above, the reactor of the present
disclosure has an excellent heat dissipation property.
[0022] On the other hand, a case will be described in which the
constituent material of the electrically insulating material and
the constituent material of the thick portion are different from
each other.
[0023] For example, if the thermal conductivity .lamda.1 of the
electrically insulating material is greater than the thermal
conductivity .lamda.2 of the thick portion, the electrically
insulating material has a more excellent thermal conductivity than
the thick portion. This kind of reactor of the present disclosure
has a more excellent heat dissipation property due to both the
magnitude relationship of the thermal conductivities and the
magnitude relationship of the intervals t1 and t2. Note that in
this case, (interval t1/thermal conductivity .lamda.1) is reliably
smaller than (interval t2/thermal conductivity .lamda.2).
[0024] Alternatively, for example, it is conceivable that the
thermal conductivity .lamda.1 of the electrically insulating
material is smaller than the thermal conductivity .lamda.2 of the
thick portion. However, it can be said that if the interval t1 is
much smaller than the interval t2, heat is likely to be transmitted
from the inner core portion to the wound portion, even if the
electrically insulating material is interposed between the inner
core portion and the wound portion. Because of this, (interval
t1/thermal conductivity .lamda.1) being smaller than (interval
t2/thermal conductivity .lamda.2) can be said to be one
configuration with an excellent heat dissipation property. In view
of this, as one configuration with an excellent heat dissipation
property, the reactor of the present disclosure envisions a
magnitude relationship between the proportions of the thermal
conductivity of the material interposed between the wound portion
and the inner core portion and the interval of the location at
which the material is arranged.
[0025] Also, the reactor of the present disclosure has excellent
manufacturability due to the following reasons. In the process of
manufacturing the reactor of the present disclosure, the resin
molded portion is formed as follows. A fluid resin that is a raw
material for the resin molded portion fills at least a portion of
the space between the wound portion and the inner core portion, and
is thereafter solidified. The space includes a location with a
relatively wide interval as a location for forming the thick
portion. For this reason, the fluid resin easily fills the space.
Consequently, the resin molded portion is easily formed.
[0026] If the electrically insulating material is a molded object
that is constituted by a material different from that of the thick
portion and is independent of the resin molded portion, the resin
molded portion is more easily formed. This kind of reactor has a
more excellent manufacturability. This is because the filling with
the fluid resin need only be performed in a state in which the
electrically insulating material is arranged in at least a portion
of the narrowest location of the space. The fluid resin does not
need to fill the region of the space in which the electrically
insulating material is present. The location at which the
electrically insulating material is not arranged in the
above-described space, that is, the relatively wide location, need
only be filled with the fluid resin. For this reason, the fluid
resin easily fills the space. Also, the fluid resin easily fills
the space accurately and with no intervals.
[0027] Furthermore, the reactor of the present disclosure also has
excellent strength for the following reasons. The magnetic core
included in the reactor of the present disclosure is held in one
piece by the resin molded portion including the inner resin portion
and the outer resin portion. The resin molded portion easily
improves the strength of the connection between the inner resin
portion and the outer resin portion using the thick portion. Due to
being held by this kind of resin molded portion, the magnetic core
can improve its rigidity as an integral object.
[0028] In addition, the reactor of the present disclosure can
achieve mechanical protection of the magnetic core, protection from
the external environment, an improvement in electrical insulation
from the coil, and the like using the resin molded portion.
[0029] As one example of a reactor of the present disclosure, a
mode is given in which the reactor includes a thin portion that is
interposed in at least a portion of the location at which the
interval between the wound portion and the inner core portion is
relatively narrow, the thin portion forming another portion of the
inner resin portion.
[0030] The above-described mode has a more excellent heat
dissipation property due to the following reasons. In the
above-described mode, a portion (thin portion) of the resin molded
portion is included at the relatively narrow location. The thermal
conductivity of the thin portion is higher than that of the air.
For this reason, the above-described mode easily improves the heat
dissipation property compared to the case where air is included in
the relatively narrow location.
[0031] As one example of the reactor according to (2), a mode is
given in which the electrically insulating material and the thin
portion are included at the location at which the interval between
the wound portion and the inner core portion is relatively
narrow.
[0032] The electrically insulating material of the above-described
mode is formed independently of the resin molded portion. In the
mode including this kind of electrically insulating material, the
resin molded portion is easily formed as described above, and thus
excellent manufacturability is achieved. In particular, the mode in
which the thermal conductivity .lamda.1 of the electrically
insulating material is higher than the thermal conductivity
.lamda.2 of the thick portion has a more excellent heat dissipation
property.
[0033] Also, in the above-described mode, the appearance of cracks
or the like in the inner resin portion due to thermal stress or the
like is easily prevented and an excellent mechanical strength is
achieved due to the following reasons. The inner resin portion
included in the above-described mode is not a ring-shaped member
that is continuous in the peripheral direction of the wound portion
in a cross-section (hereinafter referred to as a lateral
cross-sectional) obtained by cutting the reactor with a plane that
is orthogonal to the axial direction of the wound portion. The
inner resin portion is a C shape that includes a boundary with the
electrically insulating material in the above-described lateral
cross-section, and the electrically insulating material is
typically used as a break. This kind of inner resin portion can
elastically deform to a certain extent, and thus stress is easily
released. For this reason, the inner resin portion is not likely to
crack due to the thermal stress or the like.
[0034] As one example of a reactor of the present disclosure, a
mode is given in which the interval t1 of the narrowest location is
50% or less of the interval t2 of the widest location.
[0035] In the above-described mode, the interval t1 of the
narrowest location is very small compared to the interval t2. For
this reason, even if the thermal conductivity .lamda.1 is slightly
small, (interval t1/thermal conductivity .lamda.1) is likely to
decrease. In the above-described mode, (interval t1/thermal
conductivity .lamda.1) is reliably smaller than (interval
t2/thermal conductivity .lamda.2) if the thermal conductivity
.lamda.1 has a magnitude that is more than half of the thermal
conductivity .lamda.2. This kind of mode has a more excellent heat
dissipation property. Also, in the above-described mode, it is easy
to ensure a wider interval t2 of the widest location. In this kind
of mode, filling with the fluid resin is more easily performed in
the manufacturing process as described above, and a more excellent
manufacturability is achieved.
[0036] As one example of a reactor of the present disclosure, a
mode is given in which the wound portion has a quadrangular tube
shape and the inner core portion has a quadrangular column shape,
and the location at which the interval between the wound portion
and the inner core portion is relatively narrow includes a flat
plate-shaped location that is interposed between a surface of an
inner peripheral surface of the wound portion and a surface of an
outer peripheral surface of the inner core portion.
[0037] In the above-described mode, the region in which the
distance from the above-described inner core portion to the heat
dissipation location of the wound portion is short is a flat
plate-shaped region, and therefore it can be said that the region
is relatively wide. This kind of mode has a more excellent heat
dissipation property. The mode in which the electrically insulating
material formed independently of the resin molded portion is
interposed in the flat plate-shaped region also has excellent
manufacturability as described above. In particular, the mode in
which the thermal conductivity .lamda.1 of the electrically
insulating material is higher than the thermal conductivity
.lamda.2 of the thick portion has a more excellent heat dissipation
property.
[0038] As one example of a reactor of the present disclosure, a
mode is given in which the thermal conductivity .lamda.1 of the
electrically insulating material is higher than the thermal
conductivity .lamda.2 of the thick portion.
[0039] Due to the thermal conductivity .lamda.1 of the electrically
insulating material being higher than the thermal conductivity
.lamda.2 of the thick portion, in the above-described mode,
(interval t1/thermal conductivity .lamda.1) is reliably smaller
than (interval t2/thermal conductivity .lamda.2). This kind of mode
has a more excellent heat dissipation property.
[0040] As one example of a reactor of the present disclosure, a
mode is given in which the electrically insulating material
includes at least one of insulating paper and insulating film.
[0041] In general, the insulating paper and the insulating film are
very thin. For this reason, in the above-described mode, the
interval t1 of the location at which the insulating paper or the
insulating film is arranged can be made smaller. Consequently,
(interval t1/thermal conductivity .lamda.1) can be made smaller.
Accordingly, the above-described mode has a more excellent heat
dissipation property. Also, in the above-described mode, it is easy
to ensure a wider interval t2 of the widest location. For this
reason, in the above-described mode, filling with the fluid resin
is more easily performed in the manufacturing process as described
above, and more excellent manufacturability is achieved.
Furthermore, the above-described mode also has excellent electrical
insulation between the wound portion and the inner core portion.
This is because although the interval t1 is small, the insulating.
paper or the insulating film is interposed therebetween instead of
air.
[0042] As one example of a reactor of the present disclosure, a
mode is given in which the electrically insulating material
includes a molded body including a resin that is the same as a
constituent resin of the inner resin portion.
[0043] The electrically insulating material included in the
above-described mode includes a resin that is the same as that of
the inner resin portion. For this reason, the thermal conductivity
.lamda.1 is close to or substantially equal to the thermal
conductivity .lamda.2. However, since the interval t1 is smaller
than the interval t2 as described above, the above-described mode
has an excellent heat dissipation property. Also, the thermal
expansion coefficient of the above-described electrically
insulating material is close to or substantially equal to the
thermal expansion coefficient of the inner resin portion.
Accordingly, in the above-described mode, deformation, cracking,
and the like of the inner resin portion resulting from a difference
in the thermal expansion coefficient is not likely to occur, and
thus a more excellent mechanical strength is achieved. Furthermore,
the electrically insulating material is molded independently of the
resin molded portion. For this reason, in the above-described mode,
the resin molded portion is easily formed as described above, and
thus an excellent manufacturability is also achieved.
[0044] Hereinafter, embodiments of the present disclosure will be
described in detail with reference to the drawings. Objects with
the same names are denoted by the same reference numerals in the
drawings.
First Embodiment
[0045] A reactor 1 of a first embodiment will be described mainly
with reference to FIGS. 1 to 3.
[0046] FIG. 2A is a lateral cross-sectional view obtained by
cutting the reactor 1 with a plane orthogonal to an axial direction
of a coil 2. FIG. 2A shows only wound portions 2a and 2b of the
coil 2, inner core portions 31a and 31b, electrically insulating
materials 7, and inner resin portions 61. FIGS. 4A and 5, which
will be described later, are similar in this respect.
[0047] FIG. 2B is an illustrative diagram using the same drawing as
FIG. 2A. FIG. 2B is a diagram for illustrating an interval between
the wound portion 2a and the inner core portion 31a, and an
interval between the wound portion 2b and the inner core portion
31b.
[0048] In the following description, the lower portions of FIGS. 1,
2, 4, and 5 are the installation side of the reactor 1. The
installation direction is an example and can be changed as
needed.
[0049] Also, in the following description, an installation target
100 side is referred to as a lower side, and a side opposite to the
installation target 100 is referred to as an upper side in some
cases. The sides at which the wound portions 2a and 2b are near
each other are referred to as inner sides, and the sides at which
the wound portions 2a and 2b are spaced apart from each other are
referred to as outer sides in some cases.
Reactor
Overview
[0050] As shown in FIG. 1, the reactor 1 of the first embodiment
includes a coil 2 having wound portions, a magnetic core 3 that is
arranged inside and outside of the wound portions, and a resin
molded portion 6 that covers at least a portion of the magnetic
core 3. The coil 2 of the present example includes the pair of
wound portions 2a and 2b. The wound portions 2a and 2b are arranged
side by side such that their axes are parallel. The magnetic core 3
includes inner core portions 31a and 31b that are respectively
arranged in the wound portions 2a and 2b, and two outer core
portions 32 that are arranged outside of the wound portions 2a and
2b. The two outer core portions 32 are arranged so as to sandwich
the inner core portions 31a and 31b that are arranged side by side.
Due to this arrangement, the magnetic core 3 forms a ring-shaped
closed magnetic path. The resin molded portion 6 includes inner
resin portions 61 (see also FIG. 2A) and outer resin portions 62.
One inner resin portion 61 fills at least a portion between one
wound portion 2a and one inner core portion 31a. The other inner
resin portion 61 fills at least a portion between the other wound
portion 2b and the other inner core portion 31b. The outer resin
portions 62 cover at least portions of the outer core portions 32.
The resin molded portion 6 exposes the outer peripheral surfaces of
the wound portions 2a and 2b without covering them. This kind of
reactor 1 is typically used by being attached to an installation
target 100 (FIG. 2A) such as a converter case.
[0051] In the reactor 1 of the first embodiment, as shown in FIG.
2A, the interval between the wound portion 2a and the inner core
portion 31a differs in the peripheral direction of the wound
portion 2a. Also, the interval between the wound portion 2b and the
inner core portion 31b differs in the peripheral direction of the
wound portion 2b. In the reactor 1 of the present example, the
shape of the space created by the wound portion 2a and the inner
core portion 31a and the interval therebetween are substantially
equal to the shape of the space created by the wound portion 2b and
the inner core portion 31b and the interval therebetween. The
above-described spaces are tube-shaped spaces. Also, the spaces
satisfy interval g.sub.d<intervals g.sub.i and
g.sub.o<interval g.sub.de<interval g.sub.u<interval
g.sub.ue (FIG. 2B).
[0052] Furthermore, in the reactor 1 of the first embodiment, the
following specific conditions are satisfied in the interposed
object that is present at the location at which the interval is the
narrowest and the interposed object that exists at the location at
which the interval is the widest, in the intervals between the
above-described wound portions 2a and 2b and the inner core
portions 31a and 31b. Specifically, the reactor 1 includes the
electrically insulating material 7 that is interposed in a location
at which the interval is the narrowest, and a thick portion 612
that is interposed at a location at which the interval is the
widest. The thick portion 612 forms a portion of the inner resin
portion 61.
[0053] The thermal conductivity of the electrically insulating
material 7 is .lamda.1.
[0054] The interval of the narrowest location (in the present
example, interval g.sub.d) is t1.
[0055] The proportion of the interval t1 with respect to the
thermal conductivity .lamda.1 is (interval t1/thermal conductivity
.lamda.1).
[0056] The thermal conductivity of the thick portion 612 is
.lamda.2.
[0057] The interval of the widest location (in the present example,
interval g.sub.ue) is t2.
[0058] The proportion of the interval t2 with respect to the
thermal conductivity .lamda.2 is (interval t2/thermal conductivity
.lamda.2).
[0059] The reactor 1 satisfies (interval t1/thermal conductivity
.lamda.1)<(interval t2/thermal conductivity .lamda.2).
Hereinafter, each constituent element will be described in
detail.
Coil
[0060] The coil 2 of the present example includes tube-shaped wound
portions 2a and 2b that are formed by winding winding wires into
spiral shapes. The following mode is given as a coil 2 including a
pair of wound portions 2a and 2b that are arranged side by
side.
[0061] The coil 2 includes the wound portions 2a and 2b that are
formed by two independent winding wires 2w and the following
connection portion (the present example, FIG. 1). The connection
portion connects the end portions on one side of the two end
portions of the winding wires 2w pulled out from the winding
portions 2a and 2b.
[0062] The coil 2 includes the wound portions 2a and 2b that are
formed from one continuous winding wire, and a joining portion that
joins the wound portions 2a and 2b. The joining portion is composed
of a portion of the winding wire spanning between the wound
portions 2a and 2b.
[0063] In both coils 2, end portions (in (i), the other end
portions that are not used in the connection portion) of the
winding wires pulled out from the wound portions 2a and 2b are used
as locations to which an external apparatus such as a power source
is connected. Examples of the connection portion of mode (i)
include a mode in which the end portions of the winding wires 2w
are directly connected to each other, and a mode in which the end
portions of the winding wires 2w are indirectly connected to each
other. Welding, crimping, or the like can be used in the direct
connection. Suitable metal fittings or the like that are attached
to the end portions of the winding wires 2w can be used in the
indirect connection.
[0064] Examples of the winding wires 2w include covered wires that
include conductor wires and insulating coverings that cover the
outer peripheries of the conductor wires. Examples of the
constituent material of the conductor wires include copper.
Examples of the constituent material of the insulating coverings
include resins such as polyamide imide. The wound portions 2a and
2b of the present example are square tube-shaped edgewise coils
formed by winding winding wires 2w composed of covered flat wires
in an edgewise manner. Also, specifications such as the shapes,
winding directions, and numbers of turns of the wound portions 2a
and 2b of the present example are identical. Edgewise coils easily
improve the space factor, and thus it is possible to achieve a coil
2 with a smaller size. Also, due to having square tube shapes, the
outer peripheral surfaces of the wound portions 2a and 2b can
include four rectangular flat surfaces. If one of the four flat
surfaces is, for example, an installation surface, the distances
from the installation surfaces of the wound portions 2a and 2b to
the installation target 100 will be of a uniform size (FIG. 2A).
Alternatively, if the one surface is arranged near, for example, a
cooling mechanism, the distance from the one surface to the cooling
mechanism will be of a uniform size. For this reason, the wound
portions 2a and 2b can dissipate heat efficiently to the
installation target 100 and the cooling mechanism.
[0065] Note that the shapes, sizes, and the like of the winding
wires 2w and the wound portions 2a and 2b can be changed as
appropriate. For example, the winding wires may also be covered
round wires. Alternatively, for example, the shapes of the wound
portions 2a and 2b may also be tube shapes that do not have corner
portions, such as circular tube shapes or racetrack tube shapes.
The specifications of the wound portions 2a and 2b may also be
different.
[0066] In the reactor 1 of the first embodiment, the entireties of
the outer peripheral surfaces of the wound portions 2a and 2b are
exposed without being covered by the resin molded portion 6. The
inner resin portions 61, which are portions of the resin molded
portion 6, are present in the wound portions 2a and 2b. At least
portions of the inner peripheral surfaces of the wound portions 2a
and 2b are covered by the resin molded portion 6.
Magnetic Core
[0067] The magnetic core 3 of the present example includes two
column-shaped inner core portions 31a and 31b and two column-shaped
outer core portions 32. Furthermore, the magnetic core 3 of the
present example includes a gap material (not shown) between end
surfaces 31e (FIG. 3) of the inner core portions 31a and 31b and
joining surfaces 32e (FIG. 3) of the outer core portions 32. The
gap material is composed of the constituent resin of the resin
molded portion 6.
Core Pieces
[0068] As shown in FIG. 3, the inner core portions 31a and 31b of
the present example are each composed of one column-shaped core
piece. The core pieces have the same shape and the same size. Also,
the core pieces have cuboid shapes with rectangular end surfaces
31e. The outer peripheral shape of each core piece is approximately
analogous to the inner peripheral shapes of the wound portions 2a
and 2b. The corner portions of each core piece have been C
chamfered. For this reason, the corner portions of the core pieces
are not likely to be missing. This kind of core piece has excellent
strength. The corner portions of each core piece may also be R
beveled (see later-described FIG. 4A).
[0069] The outer core portions 32 of the present example are each
composed of one column-shaped core piece. The core pieces have the
same shape and the same size. The core pieces are columnar members
obtained by R beveling two corner portions of a cuboid member. The
shapes of surface on the installation target 100 side of each core
piece and the opposing surface (in FIG. 3, the upper surface and
the lower surface) are dome-shaped. The joining surface 32e at
which the inner core portions 31a and the 31b of the core pieces
are connected is a rectangular flat surface. Also, the core pieces
have a size such that the lower surfaces of the core pieces
protrude past the lower surfaces of the inner core portions 31a and
31b in a state in which the inner core portions 31a and 31b are
joined. The magnetic path of the outer core portion 32 can be
increased due to this protrusion. As a result, the size of the
reactor 1 along the axial directions of the wound portions 2a and
2b is easily reduced. In this respect, it is possible to achieve a
more compact reactor 1.
[0070] The shapes, sizes, and the like of the inner core portions
31a and 31b and the outer core portions 32 can be changed as
appropriate (see later-described modified examples 4 and 5).
[0071] In the present example, as shown in FIG. 2B, the axes Q of
the inner core portions 31a and 31b are misaligned with respect to
the axes P of the wound portions 2a and 2b. Even if the wound
portions 2a and 2b and the inner core portions 31a and 31b have
approximately analogous shapes as in the present example, if the
amount by which the axes Q are misaligned with respect to the axes
P is set, the intervals between the wound portions 2a and 2b and
the inner core portions 31a and 31b can be made different in the
peripheral directions of the wound portions 2a and 2b. The
above-described misalignment amount may be adjusted such that the
intervals fall within a desired range. The details of the intervals
will be described later.
Constituent Material
[0072] The above-described core pieces are, for example, molded
bodies mainly composed of a soft magnetic material. Examples of a
soft material include metals such as iron or an iron alloy (e.g.,
Fe--Si alloy, Fe--Ni alloy, etc.), and non-metals such as ferrite.
Examples of the above-described molded body include a pressed
powder molded body, a molded body of a composite material, a
layered body of plates composed of a soft magnetic material, and a
sintered body. A pressed powder molded body is obtained by
compression-molding a powder composed of a soft magnetic material
and a covering powder or the like including an insulating covering.
The molded body of the composite material is obtained by
solidifying a fluid mixture including a soft magnetic powder and a
resin. The layered body is obtained by stacking plate materials
such as electromagnetic steel plates. Examples of the sintered body
include a ferrite core. It is possible to use either a mode in
which the constituent materials of the inner core portions 31a and
31b and the constituent materials of the outer core portions 32 are
the same or a mode in which they are different.
[0073] The magnetic core 3 may also include a gap material as in
the present example. A solid body such as a plate material or an
air interval can be used as a gap material. Examples of constituent
materials of the solid body include, in addition to the constituent
resin of the resin molded portion 6 as in the present example, a
non-magnetic material such as alumina, or a molded body that
includes a magnetic material and has a lower relative permeability
than the above-described core piece. Note that the gap material may
also be omitted.
Interval Between Wound Portion and Inner Core Portion
[0074] Hereinafter, intervals between the wound portions 2a and 2b
and the inner core portions 31a and 31b will be described mainly
with reference to FIG. 2B.
[0075] In the present example, subject matter relating to the
interval between one wound portion 2a of the coil 2 and one inner
core portion 31a of the magnetic core 3 is substantially the same
regarding the interval between the other wound portion 2b and the
inner core portion 31b. For this reason, hereinafter, the wound
portion 2a and the inner core portion 31a will be described as
examples. Note that the interval and the later-described interposed
object between the wound portion 2a and the inner core portion 31a
can also be made different from the interval and the
later-described interposed object between the wound portion 2b and
the inner core portion 31b.
[0076] The interval between the wound portion 2a and the inner core
portion 31a in this context is the distance between the inner
peripheral surface of the wound portion 2a and the outer peripheral
surface of the inner core portion 31a.
[0077] In the present example, the inner peripheral shape of the
wound portion 2a and the outer peripheral shape of the inner core
portion 31a are approximately analogous as described above.
However, as shown in FIG. 2B, the axis Q of the inner core portion
31a is not coaxial with the axis P of the wound portion 2a but is
misaligned with respect thereto. Specifically, in the present
example, the axis Q of the inner core portion 31a is arranged
misaligned toward the installation target 100 side (lower side)
from the state in which the axis P and the axis Q are arranged
coaxially. In a sense, the inner core portion 31a is arranged
eccentrically toward the installation target 100 side. For this
reason, in the reactor 1, a location at which the interval between
the wound portion 2a and the inner core portion 31a is relatively
wide and a location at which the interval is relatively narrow are
present. In the present example, the interval toward the
installation target 100 side (lower side) is relatively narrow.
Also, in the present example, the interval toward the side opposite
to the installation target 100 (upper side) is relatively large.
The interval toward the installation target 100 is smaller than the
interval on the side opposite to the installation target 100.
[0078] In the above-described arrangement state, the interval
between the corner portion on the side opposite to the installation
target 100 (upper side) on the inner peripheral surface of the
wound portion 2a and the corner portion on the upper side of the
inner core portion 31a is g.sub.ue.
[0079] The interval between the upper surface of the inner
peripheral surface of the wound portion 2a and the upper surface of
the inner core portion 31a is g.sub.u.
[0080] The interval between the lower surface of the inner
peripheral surface of the wound portion 2a and the lower surface of
the inner core portion 31a is g.sub.d.
[0081] The interval between the corner portion on the lower side of
the inner peripheral surface of the wound portion 2a and the corner
portion on the lower side of the inner core portion 31a is
g.sub.de.
[0082] The interval between the left surface of the inner
peripheral surface of the wound portion 2a and the left surface of
the inner core portion 31a, that is, the interval on the inner
side, is g.sub.i.
[0083] The interval between the right surface of the inner
peripheral surface of the wound portion 2a and the right surface of
the inner core portion 31a, that is, the interval on the outer
side, is g.sub.o.
[0084] The interval g.sub.ue is the largest.
[0085] The interval g.sub.d is the smallest.
[0086] Also, the sizes of the intervals are, in ascending order,
intervals g.sub.i and g.sub.o, interval g.sub.de, and interval
g.sub.u. That is, the reactor 1 satisfies interval
g.sub.d<intervals g.sub.i and g.sub.o<interval
g.sub.de<interval g.sub.u<interval g.sub.ue.
[0087] Quantitatively, the reactor 1 of the present example
satisfies the following, using the interval g.sub.ue, which is the
maximum value of the interval between the wound portion 2a and the
inner core portion 31a, as a reference.
[0088] The interval g.sub.u is 80% or more and less than 100% of
the interval g.sub.ue.
[0089] The interval g.sub.de is 70% or less of the interval
g.sub.ue.
[0090] The intervals g.sub.i and g.sub.o are each 60% or less of
the interval g.sub.ue. The intervals g.sub.i and g.sub.o are equal
to each other.
[0091] The interval g.sub.d, which is the minimum value of the
above-described interval, is 40% or less of the interval
g.sub.ue.
[0092] Here, in the region between the wound portion 2a and the
inner core portion 31a, a region that is 70% or less of the maximum
value (in the present example, the interval g.sub.ue) of the
interval between the wound portion 2a and the inner core portion
31a is referred to as a location at which the interval is
relatively narrow. A region that is greater than 70% of the maximum
value of the interval is referred to as a location at which the
interval is relatively wide. FIG. 2B virtually shows a location at
which the interval is relatively narrow by adding cross-hatching
using two-dot chain lines to the location at which the interval is
relatively narrow in the region between the wound portions 2a and
2b and the inner core portions 31a and 31b. Also, in FIG. 2B, the
location at which the interval is relatively wide is denoted
virtually by adding hatching using two-dot chain lines to the
location at which the interval is relatively wide. In the present
example, the location at which the interval is relatively narrow is
a U-shaped region having the intervals g.sub.d, g.sub.i, g.sub.o,
and g.sub.de (see the cross-hatched region).
[0093] The location at which the above-described interval is
relatively narrow contributes to shortening the distance from the
inner core portion 31a to the wound portion 2a. In the present
example, the distance from the surface (lower surface) on the
installation target 100 side of the inner core portion 31a to the
surface (lower surface) on the installation target 100 side of the
outer peripheral surface of the wound portion 2a can be made
shorter compared to the case where the wound portion 2a and the
inner core portion 31a are arranged coaxially. For this reason, the
reactor 1 of the present example can dissipate heat efficiently
from the inner core portion 31a, through the wound portion 2a, and
to the installation target 100. Alternatively, in the present
example, the distance from the right surface of the inner core
portion 31a to the right surface of the outer peripheral surface of
the wound portion 2a can be made shorter than the distance from the
upper surface of the inner core portion 31a to the upper surface of
the wound portion 2a. For this reason, if the cooling mechanism is
brought close to the right surface of the outer peripheral surface
of the wound portion 2a, for example, the reactor 1 can efficiently
dissipate heat from the right surface of the inner core portion
31a, through the wound portion 2a, to the cooling mechanism. The
reactor 1 can thus shorten the distance from the inner core portion
31a to the heat dissipation location (here, the lower surface and
right surface) of the wound portion 2a.
[0094] The smaller the size (interval) of the above-described
relatively narrow location is, the more the distance from the
above-described inner core portion 31a to the heat dissipation
location of the wound portion 2a can be shortened. In this respect,
the reactor 1 has an excellent heat dissipation property. Also, the
smaller the interval of the above-described relatively narrow
location is, the easier it is to ensure a large interval of the
relatively wide location. In this respect, the resin molded portion
6 is easy to manufacture, and the reactor 1 has an excellent
manufacturability (described in detail later). If an improvement in
the heat dissipation property, an improvement in the
manufacturability, and the like are desired, the interval of the
relatively narrow location is preferably 65% or less, and more
preferably 60% or less, 55% or less, or 50% or less of the maximum
value of the above-described interval.
[0095] It is preferable that the interval t1 (here, the interval
g.sub.d) of the narrowest location of the interval between the
wound portion 2a and the inner core portion 31a is 50% or less of
the interval t2 (here, the interval g.sub.ue) of the widest
location. This is because the distance from the above-described
upper core portion 31a to the heat dissipation location of the
wound portion 2a is shorter and thus the heat dissipation property
is more excellent. Also, it is easier to ensure a wider interval t2
of the widest location. For this reason, the resin molded portion 6
is easy to manufacture, and the reactor 1 has more excellent
manufacturability. If an improvement in the heat dissipation
property, an improvement in manufacturability, and the like are
desired, the interval t1 of the narrowest location is preferably
45% or less, or more preferably 40% or less, or 35% or less of the
maximum value of the interval.
[0096] From the viewpoint of improving the heat dissipation
property and improving manufacturability, the interval t1 of the
narrowest location may also be substantially zero. However, in this
case, from the viewpoint of ensuring electrical insulation between
the wound portion 2a and the inner core portion 31a, it is
preferably that the electrical insulation is ensured by the coil 2
due to the winding wires 2w including insulating coverings, or the
like. Also, in this case, it is preferable that there is no risk of
damaging the coil 2 and the like due to vibration or the like
during use of the reactor 1.
[0097] If an improvement in the electrical insulation between the
wound portion 2a and the inner core portion 31a or the like is
desired, the interval t1 of the narrowest location may be 5% or
more, or furthermore 10% or more of the maximum value of the
interval.
[0098] In the present example, the location at which the interval
is the narrowest is a flat plate-shaped location. The interval
g.sub.d of the flat plate-shaped location is 5% or more and 50% or
less of the maximum value of the interval.
[0099] The greater the percentage occupied by the location at which
the interval is relatively narrow in the region between the wound
portion 2a and the inner core portion 31a is, the more excellent
the heat dissipation property is. This is because the number of
regions in which the distance from the above-described inner core
portion 31a to the heat dissipation location of the wound portion
2a is short increases. Examples of modes in which the
above-described occupation percentage is great includes a case in
which the percentage of the length of the location at which the
interval is relatively narrow (hereinafter referred to as "length
percentage") with respect to the inner peripheral length of the
wound portion 2a is 10% or more. The length of the location at
which the interval is relatively narrow is the length along the
peripheral direction of the wound portion 2a. The greater the
length percentage is, the more regions there are in which the
distance to the above-described heat dissipation location is short.
In this respect, the reactor 1 easily improves the heat dissipation
property. If an improvement in the heat dissipation property is
desired, it is preferable that the above-described length
percentage is 15% or more. In the present example, the length
percentage is 50% or more, and furthermore 65% or more. For this
reason, it can be said that the reactor 1 of the present example
includes many regions in which the interval is relatively narrow.
On the other hand, if the length percentage is, for example, 90% or
less, a location in which the interval is relatively wide reliably
exists. Consequently, the thick portion 612 reliably exists. If an
increase in the presence percentage of the thick portion 612 or the
like is desired, the length percentage may also be 85% or less, and
furthermore 80% or less. In addition, in the present example, the
percentage of the length of the location at which the interval is
the widest with respect to the inner peripheral length of the wound
portion 2a is 15% or more.
[0100] Other examples of a mode in which the above-described
occupation percentage is high include a case in which the location
at which the interval is relatively narrow includes the following
flat plate-shaped location as in the present example. Specifically,
the wound portion 2a has a quadrangular tube shape. The inner core
portion 31a has a quadrangular column shape. The flat plate-shaped
location is a location that is sandwiched between one surface
(here, the surface on the installation target 100 side (lower
surface)) of the inner peripheral surface of the wound portion 2a
and one surface (lower surface) of the outer peripheral surface of
the inner core portion 31a. The flat plate-shaped location has a
surface area that is approximately equal to that of the lower
surface of the wound portion 2a. For this reason, it can be said
that this mode has a very high number of regions in which the
distance from the above-described inner core portion 31a to the
heat dissipation location of the wound portion 2a is short. In this
respect, the reactor 1 easily improves the heat dissipation
property. Also, in the present example, the interval g.sub.d of the
flat plate-shaped location is 40% or less of the maximum value of
the interval, and is half or less of the maximum value of the
interval. In this respect as well, the reactor 1 easily improves
the heat dissipation property.
Interposed Member
[0101] The reactor 1 of the present example includes the interposed
member 5. The interposed members 5 are interposed between the wound
portions 2a and 2b of the coil 2 and the magnetic core 3. The
interposed members 5 of the present example are typically composed
of an electrically insulating material, and contribute to improving
the electrical insulation between the coil 2 and the magnetic core
3. The interposed members 5 contribute also to positioning the
magnetic core with respect to the wound portions 2a and 2b.
Furthermore, in the manufacturing process of the reactor 1, the
interposed members 5 of the present example contribute also to
forming predetermined intervals between the wound portions 2a and
2b and the inner core portions 31a and 31b, between the inner core
portions 31a and 31b and the outer core portions 32, and the like.
This interval is used as a flow path of the fluid resin. The fluid
resin filling the interval is solidified to form the resin molded
portion 6.
[0102] Specifically, the interposed member 5 of the present example
is a frame-shaped plate member as shown in FIG. 3 and is arranged
between the end surfaces of the wound portions 2a and 2b and the
joining surfaces 32e of the outer core portions 32 (see also FIG.
1). In the plate material, two through holes 5h are provided side
by side in a direction orthogonal to the axial directions of the
wound portions 2a and 2b. Multiple support pieces 51 are provided
toward the wound portions 2a and 2b in the plate material. The
support pieces 51 position the inner core portions 31a and 31b. The
plate material includes the multiple support pieces and recessed
portions 54 toward the outer core portions 32. The support pieces
52 prevent misalignment of the outer core portions 32. The outer
core portions 32 are fit into the recessed portions 54. The support
pieces 51 and 52 are omitted in FIG. 1.
[0103] The through holes 5h of the present example are holes that
are plus-shaped in a view in their axial directions. Specifically,
the through holes 5h have plus shapes due to the four corners of
each square-shaped hole being covered by flat plate-shaped end
surface support portions 53. In the state in which the inner core
portions 31a and 31b and the interposed member 5 are assembled, the
four corner portions of each of the end surfaces 31e of the inner
core portions 31a and 31b are covered by the end surface support
portions 53. Locations other than the four corner portions of each
of the end surfaces 31e are exposed from the through holes 5h. A
predetermined interval is formed between the outer peripheral
surface of the inner core portions 31a and 31b and the opening
edges of the through holes 5h. This interval is used as a flow path
of the above-described fluid resin. Also, in the above-described
assembled state, the end surface support portions 53 are interposed
between the end surfaces 31e of the inner core portions 31a and 31b
and the joining surfaces 32e of the outer core portions 32. Due to
this interposition, intervals corresponding to the thickness of the
end surface support portions 53 are formed between the end surfaces
31e and the joining surfaces 32e. These intervals are used as
locations for forming gaps composed of the constituent resin of the
resin molded portion 6. The thickness of end surface support
portions 53 is adjusted according to the gap length.
[0104] The interposed member 5 includes multiple support pieces 51
(eight support pieces 51 in total). Each support piece 51 protrudes
toward the wound portion 2a or 2b from a corner portion near the
opening edge of a through hole 5h. Four support pieces 51 protrude
from the corner portions near one opening edge. The support pieces
51 are rod-shaped members that extend along the axial directions of
the wound portions 2a and 2b. The inner peripheral surfaces of the
support pieces 51 have shapes that correspond to the corner
portions of the outer peripheral surfaces of the inner core
portions 31a and 31b. In the state in which the coil 2, the
magnetic core 3, and the interposed member 5 are assembled, the
above-described four support pieces 51 support the corner portions
near the end surface 31e of the outer peripheral surface of one
inner core portion 31a (or 31b). Due to this support, the inner
core portions 31a and 31b are positioned at a predetermined
position with respect to the wound portions 2a and 2b. Also, the
intervals between the wound portions 2a and 2b and the inner core
portions 31a and 31b are set to a predetermined size.
[0105] In the present example, the thicknesses of the
above-described four support pieces 51 are different. Specifically,
the thicknesses of the support pieces 51 arranged on the
installation target 100 side (lower side) are thinner than the
thicknesses of the support pieces 51 arranged on the side opposite
to the installation target 100 (upper side) (see the interposed
member 5 on the right side in FIG. 3). Due to the inner core
portions 31a and 31b being supported by this kind of support piece
51, the intervals between the wound portions 2a and 2b and the
inner core portions 31a and 31b are suitably maintained at the
above-described size (see also FIG. 2A).
[0106] In addition, in the present example, groove portions into
which the vicinity of the end portions of the wound portions 2a and
2b and portions of the winding wires 2w are fit are provided in
regions toward the wound portions 2a and 2b in the interposed
members 5 (see the interposed member 5 on the right side in FIG.
3). Portions of the above-described winding wires 2w are pulled-out
portions of the winding wires 2w that have been pulled out from the
wound portions 2a and 2b. Due to the vicinities of the end portions
of the wound portions 2a and 2b and the pulled-out portions being
fit into the groove portions, the wound portions 2a and 2b are
accurately positioned with respect to the interposed members 5. The
positions of the inner core portions 31a and 31b with respect to
the wound portions 2a and 2b are also accurately determined via the
interposed member 5. For this reason, the reactor 1 can accurately
maintain the intervals between the wound portions 2a and 2b and the
inner core portions 31a and 31b.
[0107] The two support pieces 52 arranged on the outer core portion
32 side in the interposed member 5 prevent vertical positional
misalignment of the outer core portions 32. The support pieces 52
are flat plate-shaped tongue pieces. The two support pieces 52 are
arranged so as to sandwich the upper surface and the lower surface
of the outer core portion 32. The joining surface 32e of the outer
core portion 32 and its vicinity are accommodated in a recessed
portion 54 that is provided on the outer core portion 32 side of
the interposed member 5. The shape and size of the recessed portion
54 are adjusted such that a predetermined interval is provided
between the outer peripheral surface of the outer core portion 32
and the inner wall of the inner portion 54 in the state in which
the outer core portion 32 is accommodated in the recessed portion
54. This interval is a space that is in communication with the
interval forming the above-described gap and the intervals between
the inner core portions 31a and 31b and the opening edges of the
through holes 5h. These intervals are used as flow paths of the
above-described fluid resin. The above-described through holes 5h
open on the bottom surface of the recessed portion 54. Also, the
joining surface 32e of the outer core portion 32 abuts on the
bottom surface of the recessed portion 54.
[0108] The interposed member 5 shown in FIG. 3 is an example, and
the shape, size, and the like of the interposed member 5 can be
changed as appropriate.
Constituent Material
[0109] Examples of the constituent material of the interposed
member 5 include an electrically insulating material. Examples of
the electrically insulating material include various types of
resin. Examples of resin include thermoplastic resin and
thermosetting resin. Specific examples of thermoplastic resin
include polyphenylene sulfide (PPS) resin, polytetrafluoroethylene
(PTFE) resin, liquid crystal polymer (LCP), polyamide (PA) resins
such as nylon 6 and nylon 66, polybutylene terephthalate (PBT)
resin, and acrylonitrile butadiene styrene (ABS) resin. Specific
examples of thermosetting resin include unsaturated polyester
resin, epoxy resin, urethane resin, and silicone resin. The
interposed member 5 can be manufactured using a known molding
method such as injection molding.
Resin Molded Portion
[0110] Due to including inner resin portions 61 that cover at least
portions of the inner core portions 31a and 31b and outer resin
portions 62 that cover at least portions of the outer core portions
32, the resin molded portion 6 exhibits, for example, the following
effects.
(A) The resin molded portion 6 mechanically protects the core
pieces. (B) The resin molded portion 6 protects the core pieces
from the external environment (improves corrosion resistance). (C)
The resin molded portion 6 improves the insulation between the core
pieces, the coil 2, and the surrounding parts.
[0111] The inner resin portions 61 of the present example mainly
cover the regions of the outer peripheral surfaces of the inner
core portions 31a and 31b other than portions of the end surfaces
31e and the locations supported by the interposed member 5. The
outer resin portions 62 of the present example mainly cover the
regions of the outer peripheral surfaces of the outer core portions
32 other than the joining surfaces 32e. Since a wide range of the
outer peripheral surface of the magnetic core 3 is covered by the
resin molded portion 6, the reactor 1 of the present example more
easily obtains the above-described effect.
[0112] Also, the resin molded portion 6 of the present example is
an integrated object in which the inner resin portions 61 and the
outer resin portions 62 are formed continuously with each other.
Also, the resin molded portion 6 of the present example integrally
holds the set composed of the magnetic core 3 and the interposed
member 5. For this reason, the resin molded portion 6 contributes
also to an improvement in the strength of the integrated object of
the set. Furthermore, a portion of the resin molded portion 6 of
the present disclosure functions also as a magnetic gap as
described above.
[0113] In particular, in the reactor 1 of the first embodiment, the
thickness of the inner resin portion 61 differs in the peripheral
direction, and the reactor 1 includes the thin portions 610 and the
thick portions 612 (FIG. 2A). The thick portions 612 include the
location at which the interval is the widest in the interval
between the wound portions 2a and 2b and the inner core portions
31a and 31b, and a portion of the inner resin portion 61 is formed
by filling the location at which the interval is relatively wide.
The thin portion 610 forms the other portion of the inner resin
portion 61 by filling at least a portion of the location at which
the interval is relatively narrow.
Inner Resin Portion
[0114] The inner resin portion 61 of the present example is present
in at least a portion of a tube-shaped space provided between the
inner peripheral surface of the wound portion 2a (or 2b) and the
outer peripheral surface of the inner core portion 31a (or 31b).
That is, the inner resin portions 61 are present in the wound
portions 2a and 2b. The inner resin portions 61 are formed by
filling the tube-shaped space with a fluid resin serving as the raw
material of the resin molded portion 6. In the present example, the
electrically insulating material 7 is present in a portion of the
tube-shaped space. For this reason, the inner resin portion 61 is
C-shaped in a lateral cross section (FIG. 2A). The thickness of the
inner resin portion 61 corresponds to the size of the tube-shaped
space. That is, the thickness of the inner resin portion 61
corresponds to the interval between the wound portion 2a (or 2b)
and the inner core portion 31a (or 31b) and is not a constant
thickness along the peripheral direction of the wound portion 2a
(or 2b). The thickness of the inner resin portion 61 is thin on the
installation target 100 side (lower side) and is thick on the side
opposite to the installation target 100 (upper side), as shown in
FIG. 2A. The thickness will be described in detail later.
Outer Resin Portion
[0115] The outer resin portion 62 of the present example covers
substantially the entirety of the outer peripheral surface of the
outer core portion 32 along the outer core portion 32 (core
pieces), except for the connecting surface 32e and the vicinity
thereof. That is, the outer resin portions 62 are exposed without
being covered by the wound portions 2a and 2b. Also, the outer
resin portions 62 of the present example have an approximately
uniform thickness. The covered region, thickness, and the like of
the outer core portion 32 on the outer resin portion 62 can be
selected as appropriate.
Constituent Material
[0116] Examples of the constituent material of resin molded portion
6 include various resins. Examples of resin include thermoplastic
resin. Specific examples of thermoplastic resin include PPS resin,
PTFE resin, LCP, PA resins such as nylon 6, nylon 66, nylon 10 T,
nylon 9 T, and nylon 6 T, and PBT resin. The constituent material
may also be a composite material containing the above-described
resin and a filler with excellent thermal conductivity (e.g., a
filler composed of alumina or silica, etc.). Due to including the
filler, it is possible to achieve a resin molded portion 6 with an
excellent heat dissipation property. The constituent material of
the resin molded portion 6 and the constituent material of the
interposed member 5 may also include the same resin. Due to
including the same resin, both the resin molded portion 6 and the
interposed member 5 have excellent bondability. Also, due to
including the same resin, the thermal expansion coefficients of the
resin molded portion 6 and the interposed member 5 are close to or
substantially equal to each other. For this reason, separation due
to thermal stress, cracking of the resin molded portion 6, and the
like can be suppressed. Injection molding or the like can be used
in the molding of the resin molded portion 6.
Interposed Object Between Wound Portion and Inner Core Portion
[0117] In the present example, subject matter relating to the
interposed object between one wound portion 2a of the coil 2 and
one inner core portion 31a of the magnetic core 3 is substantially
the same regarding the interposed object between the other wound
portion 2b and the other inner core portion 31b. For this reason,
hereinafter, the wound portion 2a and the inner core portion 31a
will be described as examples.
[0118] The reactor 1 of the present example includes the inner
resin portion 61 and the electrically insulating material 7 between
the wound portion 2a and the inner core portion 31a. Specifically,
the reactor 1 includes a thick portion 612, which is a portion of
the inner resin portion 61, over the entire location at which the
above-described interval is relatively wide. The reactor 1 includes
a thin portion 610, which is the remaining portion of the inner
resin portion 61, at a portion of the location at which the
interval is relatively narrow, and includes the electrically
insulating material 7 at another portion. In particular, the
reactor 1 includes the narrowest flat plate-shaped electrically
insulating material 7 in the location at which the interval is
relatively thin. The electrically insulating material 7 of the
present example is a molded body that is independent of the resin
molded portion 6.
Inner Resin Portion
[0119] The inner resin portion 61 of the present example is
constituted by a uniform resin. For this reason, the thermal
characteristics of the inner resin portion 61 are uniform. The thin
portion 610 and the thick portion 612 have a thermal conductivity
.lamda.2. The thin portion 610 of the present example is present in
the region having the intervals g.sub.i, g.sub.o, and g.sub.de. For
this reason, the thin portion 610 has a thickness that corresponds
to the intervals g.sub.i, g.sub.o, and g.sub.de. The thick portion
612 of the present example is present in a region (region that is
only hatched and not cross-hatched in FIG. 2B) excluding the
location at which the interval is relatively narrow out of the
region between the wound portion 2a and the inner core portion 31a.
That is, the thick portion 612 is present in the region having the
intervals g.sub.ue and g.sub.u. For this reason, the thick portion
612 has a thickness that corresponds to the intervals g.sub.ue and
g.sub.u. The thickest location of the thick portion 612 has a
thickness that corresponds to the interval g.sub.ue (=interval
t2).
Electrically Insulating Material
[0120] The electrically insulating material 7 is composed of
various electrically insulating materials. Due to the electrically
insulating material 7 being interposed between the wound portion 2a
and the inner core portion 31a, the electrical insulation of the
wound portion 2a and the inner core portion 31a can be
improved.
Constituent Material
[0121] .lamda.1=.lamda.2
[0122] Examples of the electrically insulating material 7 include a
molded body including a resin that is the same as the constituent
resin of the inner resin portion 61. The thermal conductivity
.lamda.1 of the electrically insulating material 7 is substantially
the same as the thermal conductivity .lamda.2 of the thick portion
612 (.lamda.1=.lamda.2). On the other hand, the interval t1 (here,
interval g.sub.d) of the location at which the electrically
insulating material 7 is arranged is smaller than the interval t2
(here, interval g.sub.ue) of the location at which the thick
portion 612 is arranged (t1<t2). Accordingly, this mode
satisfies (interval t1/thermal conductivity .DELTA.1)<(interval
t2/thermal conductivity .lamda.2) and an excellent heat dissipation
property is achieved. In particular, the smaller the interval t1
is, the more excellent the heat dissipation property is.
[0123] Also, if the electrically insulating material 7 is the
molded body including the resin, the electrical insulation between
the wound portion 2a and the inner core portion 31a can be improved
by both the inner resin portion 61 and the electrically insulating
material 7. Furthermore, in this case, the set composed of the
inner resin portion 61 and the electrically insulating material 7
can improve the mechanical strength. The thermal expansion
coefficient of the inner resin portion 61 and the thermal expansion
coefficient of the electrically insulating material 7 are
substantially equal to each other. For this reason, deformation,
cracking, and the like of the inner resin portion 61 accompanying a
difference in the thermal expansion coefficients are not likely to
occur. In the case where the constituent material of the inner
resin portion 61 includes the composite resin including the
above-described filler, the difference from the thermal expansion
coefficient of the inner resin portion 61 is easily reduced if the
electrically insulating material 7 uses at least the resin
component in common. If the electrically insulating material 7 is
composed of the composite resin including the filler and the filler
also has excellent electrical insulation, excellent electrical
insulation is achieved.
.lamda.1>.lamda.2
[0124] Other examples of the electrically insulating material 7
include an electrically insulating material composed of a
constituent material with a higher thermal conductivity than the
constituent material of the inner resin portion 61. The thermal
conductivity .lamda.1 of the electrically insulating material 7 is
higher than the thermal conductivity .lamda.2 of the inner resin
portion 61 (thick portion 612) (.lamda.1>.lamda.2). Also, the
interval t1 is smaller than the interval t2 as described above.
Accordingly, this mode satisfies (interval t1/thermal conductivity
.lamda.1)<(interval t2/thermal conductivity .lamda.2). In
particular, the electrically insulating material 7 is arranged at
the narrowest location out of the location at which the interval is
relatively narrow. For this reason, the reactor 1 can efficiently
perform heat transmission from the inner core portion 31a, through
the electrically insulating material 7, and to the wound portion
2a. Accordingly, this mode has a more excellent heat dissipation
property. In particular, the greater the thermal conductivity
.lamda.1 is, the more excellent the heat dissipation property is.
Also, the smaller the interval t1 is, the more excellent the heat
dissipation property is.
[0125] Examples of the constituent material of the electrically
insulating material 7 with the high thermal conductivity include a
composite resin including the above-described fillers, and various
ceramics. Examples of the ceramics include alumina and aluminum
nitride. A plate material composed of the composite resin or the
ceramics can be used as the electrically insulating material 7. In
addition, the electrically insulating material 7 made of resin may
also be various heat dissipation sheets or the like composed of
silicone resin or the like. If an electrically insulating material
7 including an adhesive layer on one surface of a heat dissipation
sheet or one surface of a ceramic plate is used, the reactor 1 has
excellent manufacturability. The electrically insulating material 7
including the adhesive layer can be adhered to the outer peripheral
surface of the inner core portion 31a in the process of
manufacturing the reactor 1. For this reason, the inner core
portion 31a and the electrically insulating material 7 can be
simultaneously inserted into the wound portion 2a. In addition,
examples of the electrically insulating material 7 with high
thermal conductivity include an electrically insulating material 7
that includes an insulating layer on an outer surface of a base
material composed of metal. Examples of the metal include aluminum
or an alloy thereof. Examples of the constituent material of the
insulating layer include various resins and ceramics such as
alumina.
.lamda.1<.lamda.2
[0126] Yet other examples of the electrically insulating material 7
include an electrically insulating material 7 with a thermal
conductivity that is less than the thermal conductivity .lamda.2 of
the inner resin portion 61 (thick portion 612)
(.lamda.1<.lamda.2). The electrically insulating material 7 is
arranged at the location at which the interval is the narrowest.
For this reason, even if the electrically insulating material 7
does not have a thermal conductivity that is greater than or equal
to the thermal conductivity .lamda.2 of the inner resin portion 61,
if (interval t1/thermal conductivity .lamda.1)<(interval
t2/thermal conductivity .lamda.2) is satisfied, heat can be
dissipated to the wound portion 2a due to the distance from the
inner core portion 31a to the wound portion 2a being short. In this
mode, the smaller the interval t1 is, the more excellent the heat
dissipation property is. Also, it is more preferable the greater
the thermal conductivity .lamda.1 is within a range of satisfying
.lamda.1<.lamda.2. Depending on the size of the interval t1, if
the thermal conductivity .lamda.2 is at most 2.5 times the thermal
conductivity .lamda.1, and furthermore less than 2 times the
thermal conductivity .lamda.1, (interval t1/thermal conductivity
.lamda.1) is likely to be smaller than (interval t2/thermal
conductivity .lamda.2).
[0127] Examples of the electrically insulating material 7 that
satisfies .lamda.1<.lamda.2 include insulating paper and
insulating film. Very thin insulating paper and insulating film are
commercially available. Examples of the thickness include 10 .mu.m
or more and 200 .mu.m or less, and furthermore 180 .mu.m or less,
150 .mu.m or less, and 100 .mu.m or less. If the electrically
insulating material 7 is thin in this manner, the interval t1 can
also be made thin according to the thickness of the electrically
insulating material 7. For this reason, (interval t1/thermal
conductivity .lamda.1) can be made much smaller than (interval
t2/thermal conductivity .lamda.2), and thus the reactor 1 can
improve the heat dissipation property.
[0128] Examples of the insulating paper include insulating paper
including cellulose fibers or aramid fibers. Examples of the
insulating film include insulating film composed of resin such as
polyethylene terephthalate (PET), polyethylene naphthalate (PEN),
or polyimide. It is possible to use a commercially-available
insulating paper or a commercially-available insulating film. It is
preferable that the electrically insulating material 7 is used by
cutting the insulating paper or the insulating film according to
the size of arrangement location. If an insulating film including
an adhesive layer or the like is used, the reactor 1 also has
excellent manufacturability as described above.
Shape
[0129] The electrically insulating material 7 of the present
example is a flat plate material. The flat plate material has a
thickness that is approximately equal to the interval g.sub.d.
Also, the flat plate material has a surface area that is
approximately equal to that of the location that is not covered by
the interposed member 5 on the surface (lower surface) on the
installation target 100 side of the inner core portion 31a. The
flat plate-shaped electrically insulating material 7 is located so
as to approximately fill the space between the surface (lower
surface) on the installation target 100 side of the inner
peripheral surface of the wound portion 2a and the lower surface of
the inner core portion 31a. In addition, the electrically
insulating material 7 may also be, for example, a rod material
instead of the flat plate material.
Number
[0130] The reactor 1 of the present example includes one
electrically insulating material 7 per wound portion 2a. Due to the
number of the electrically insulating material 7 being small, the
reactor 1 has excellent manufacturability. This is because it is
easy to shorten assembly time in the process of manufacturing the
reactor 1. Due to the fact that the electrically insulating
material 7 of the present example is a flat plate material and can
easily be arranged in a flat plate-shaped location as well, the
reactor 1 has excellent manufacturability. The reactor 1 may also
include multiple electrically insulating materials 7 with respect
to one wound portion 2a. For example, if the electrically
insulating material 7 is the above-described rod material, the
reactor 1 may also include multiple rod materials spaced apart in
the peripheral direction of the wound portion 2a.
Occupation Percentage
[0131] The percentage occupied by the electrically insulating
material 7 with respect to the location in which the interval is
relatively narrow in the one wound portion 2a, that is, the
percentage occupied by the electrically insulating material 7 at
the narrowest location can be selected as appropriate. For example,
the occupation percentage is the area percentage in a lateral
cross-section, and may be 5% or more and 95% or less. The lateral
cross-sectional area of the location in which the interval is
relatively narrow has an occupation percentage of 100%. In the
illustration shown in FIG. 2B, the U-shaped location denoted by
cross-hatching has an occupation percentage of 100%. Also, if
multiple electrically insulating materials 7 are included, the
occupation percentage is the percentage of the total area of the
multiple electrically insulating materials 7. The occupation
percentage in this example is the area percentage in a lateral
cross-section, and is 5% or more and 30% or less. It can be said
that this kind of reactor 1 has, to a certain extent, many thin
portions 610 at the location at which the interval is relatively
narrow. Due to there being many thin portions 610, and
consequently, many inner resin portions 61 to a certain extent, it
is easy to improve the strength of the magnetic core 3 using the
resin molded portion 6. This is because if the multiple core pieces
are integrated by the resin molded portion 6 as in the present
example, the strength of the integral object of the magnetic core 3
is easily increased. On the other hand, the occupation percentage
of the electrically insulating material 7 may also be greater in
the above-described range (5% to 95%). That is, the percentage of
the thin portions 610 may also be small. In this case, the resin
molded portion 6 has excellent manufacturability. This is because
there are few relatively narrow locations in the filling location
of the fluid resin and thus it is easier to fill with the fluid
resin.
[0132] The shape and size of the electrically insulating material
7, the arrangement position and number of the electrically
insulating materials 7 at the location at which the interval is
relatively narrow, the occupation percentage of the electrically
insulating material 7 with respect to the location at which the
interval is relatively narrow, and the like can be selected as
appropriate.
Other
[0133] In the reactor 1 of the present example, substantially only
the electrically insulating material 7 exists at the narrowest
location of the location at which the interval is relatively
narrow. With this kind of reactor 1, the resin molded portion 6 is
easily manufactured and an excellent manufacturability is achieved.
In the process of manufacturing the reactor 1, if the resin molded
portion 6 is formed in at state in which the electrically
insulating material 7 is arranged at the narrowest location, the
locations other than the narrowest location can be made into flow
paths for the fluid resin. For this reason, the flow paths easily
become relatively wide. Accordingly, the flow paths are easily
filled with the fluid resin.
[0134] Note that the electrically insulating material 7 and a
portion of the resin molded portion 6 can also be included at the
narrowest location. However, from the viewpoint of
manufacturability, it is preferable that the narrowest location
includes only the electrically insulating material 7.
Method for Manufacturing Reactor
[0135] The reactor 1 of the first embodiment is manufactured as
follows, for example. A combined body 10 including the coil 2, the
magnetic core 3, and the electrically insulating material 7 is
produced (FIG. 3). The combined body 10 is accommodated in a mold
(not shown) of the resin molded portion 6. The magnetic core 3 is
covered with the fluid resin while the outer peripheral surface of
the wound portions 2a and 2b of the coil 2 are exposed. The fluid
resin is solidified to form the resin molded portion 6.
[0136] The combined body 10 of the present example includes the
interposed member 5. By using the interposed member 5, the combined
body 10 can be easily constructed. Specifically, the wound portions
2a and 2b are arranged in the groove portions of the interposed
member 5. The inner core portions 31a and 31b are attached until
they abut on the end surface support portions 53. The outer core
portions 32 are accommodated in the recessed portions 54. The coil
2 and the magnetic core 3 can be easily positioned with respect to
the interposed member 5 in this manner. Also, in the present
example, the inner core portions 31a and 31b and the electrically
insulating materials 7 are sequentially inserted into the wound
portions 2a and 2b. Alternatively, the electrically insulating
materials 7 are bonded to the inner core portions 31a and 31b in
advance, and the bonded results are simultaneously inserted into
the wound portions 2a and 2b. By doing so, it is possible to
construct a combined body 10 in which the inner core portions 31a
and 31b and the electrically insulating materials 7 are present in
the winding. portions 2a and 2b.
[0137] For example, the fluid resin may be introduced into the
combined body 10 accommodated in the mold in one direction from the
outer end surface of the one outer core portion 32 to the outer end
surface of the other outer core portion 32. Alternatively, the
fluid resin may be introduced in two directions from the outer end
surfaces of the two outer core portions 32 to the wound portions 2a
and 2b. In either case, the fluid resin sequentially flows into the
gaps below to fill the gaps from the outer end surface of the outer
core portion 32. First, the fluid resin flows into the gap between
the outer peripheral surface of the outer core portion 32 and the
inner wall of the recessed portion 54 of the interposed member 5.
Next, the fluid resin flows through the gap created by the
interposition of the end surface support portion 53 and into the
gap between the wound portions 2a and 2b of the coil 2 and the
outer peripheral surfaces of the inner core portions 31a and 31b.
After the filling with the fluid resin, the resin molded portion 6
is formed by solidifying the fluid resin.
Application
[0138] The reactor 1 of the first embodiment can be used as a
component of a circuit that performs a voltage step-up operation or
a voltage step-down operation, and for example, can be used as a
constituent component of various types of converters and power
conversion apparatuses. Examples of converters include an
in-vehicle converter (typically a DC-DC converter) mounted in a
vehicle such as a hybrid automobile, a plug-in hybrid automobile,
an electric automobile, or a fuel call automobile, and a converter
for an air conditioner.
Effect
[0139] The reactor 1 of the first embodiment has an excellent heat
dissipation property.
[0140] The outer peripheral surfaces of the wound portions 2a and
2b of the coil 2 are exposed substantially without being covered by
the resin molded portion 6. For this reason, the wound portions 2a
and 2b can come into direct contact with a liquid refrigerant or a
fluid refrigerant such as wind from a fan, or can be brought close
to the installation target 100 or a cooling mechanism, and thus
have an excellent heat dissipation efficiency.
[0141] A relatively narrow location is present between the wound
portions 2a and 2b of the coil 2 and the inner core portions 31a
and 31b of the magnetic core 3. The narrowest location of the
relatively narrow location is provided at a position corresponding
to the installation target 100 side of the wound portions 2a and
2b. For this reason, the distances from the inner core portions 31a
and 31b to the heat dissipation locations of the wound portions 2a
and 2b are short. As a result, the reactor 1 can efficiently
dissipate heat from the inner core portions 31a and 31b to the
wound portions 2a and 2b, and can further dissipate heat to the
installation target 100.
[0142] The other portion of the relatively narrow location is
provided at a position corresponding to the surface (in the wound
portion 2a of FIG. 2A, the right surface; in the wound portion 2b,
the left surface) on the side from which both of the wound portions
2a and 2b are spaced apart. For this reason, if the cooling
mechanism is brought close to the sides of the wound portions 2a
and 2b, for example, the distances to the heat dissipation
locations of the wound portions 2a and 2b are short. As a result,
the reactor 1 can efficiently dissipate heat from the inner core
portions 31a and 31b to the wound portions 2a and 2b, and can
further dissipate heat to the cooling mechanism.
[0143] The reactor 1 satisfies (interval t1/thermal conductivity
.lamda.1)<(interval t2/thermal conductivity .lamda.2). For this
reason, an excellent heat dissipation. ability is achieved not only
in the case where the thermal conductivity .lamda.1 of the
electrically insulating material 7 is greater than or equal to the
thermal conductivity .lamda.2 of the thick portion 612, but also in
the case where the thermal conductivity .lamda.1 is smaller than
the thermal conductivity .lamda.2.
[0144] The reactor 1 of the present example has an excellent heat
dissipation property due to the following reasons.
[0145] The reactor 1 includes the thin portion 610 at a location
that is relatively narrow. For this reason, the reactor 1 has a
more excellent heat dissipation property compared to the case where
air is included in the relatively narrow location.
[0146] The surfaces of the wound portions 2a and 2b on the
installation target 100 side and the surfaces on the sides spaced
apart from each other are flat plate-shaped surfaces. For this
reason, the heat dissipation areas of the wound portions 2a and 2b
are wide, and the reactor 1 has a more excellent heat dissipation
efficiency.
[0147] If the thermal conductivity .lamda.1 of the electrically
insulating material 7 is greater than the thermal conductivity
.lamda.2 of the thick portion 612, the reactor 1 has a more
excellent heat dissipation property.
[0148] The reactor 1 of the present embodiment further exhibits the
following effects.
[0149] The reactor 1 has excellent manufacturability.
[0150] The reactor 1 includes a relatively wide location as the
forming location of the thick portion 612 in the spaces between the
wound portions 2a and 2b and the inner resin portions 61. For this
reason, in the reactor 1, the fluid resin, which is the raw
material of the resin molded portion 6, easily fills the spaces,
and the resin molded portion 6 is easily formed.
[0151] The electrically insulating material 7 is a molded body that
is independent of the resin molded portion 6. For this reason,
there is no need to fill the narrowest location in the space with
the fluid resin, filling with the fluid resin is easy, and filling
can be performed accurately.
[0152] The reactor 1 includes the interposed member 5 on which
multiple support pieces 51 with different thicknesses are provided.
For this reason, the reactor 1 can efficiently and easily mold the
inner resin portion 61 that has a predetermined thickness
corresponding to the size of a predetermined interval by adjusting
the thickness of the support piece 51 of the interposed member 5
according to the interval.
[0153] The reactor 1 includes the interposed member 5 that has the
above-described predetermined shape. For this reason, the reactor 1
can easily position the coil 2 and the magnetic core 3 via the
interposed member 5, and thus is easy to assemble.
[0154] The reactor 1 has excellent mechanical strength due to
including the electrically insulating material 7, which is a molded
body that is independent of the resin molded portion 6. The lateral
cross-section of the inner resin portion 61 is C-shaped. For this
reason, the inner resin portion 61 can elastically deform to a
certain extent. As a result, the reactor 1 easily prevents the
occurrence of cracking and the like in the inner resin portion 61
resulting from thermal stress and the like.
[0155] In addition, the reactor 1 of the first embodiment can
achieve mechanical protection of the magnetic core 3, protection
from the external environment, an improvement in electrical
insulation from the coil 2, and the like with the resin molded
portion 6.
Second Embodiment
[0156] A reactor of a second embodiment will be described with
reference to FIGS. 4A and 4B.
[0157] FIG. 4B is an illustrative diagram using a drawing that is
the same as that of FIG. 4A. FIG. 4B is a diagram for illustrating
an interval between the wound portions 2a and 2b and the inner core
portions 31a and 32b.
[0158] As shown in FIG. 4A, the basic configuration of the reactor
of the second embodiment is similar to that of the reactor 1 (see
FIG. 2A) of the first embodiment. In the reactor of the second
embodiment, one difference from the first embodiment is that the
inner core portions 31a and 31b are distributed unevenly at the
corner portions on the sides (inner sides) at which the wound
portions 2a and 2b are close to each other. Also, another
difference is that the interval t1 of the narrowest location of the
interval between the wound portions 2a and 2b and the inner core
portions 31a and 31b is smaller than that in the first
embodiment.
[0159] Hereinafter, the differences will mainly be described, and
detailed description of configurations and effects that are
redundant with those of the first embodiment will be omitted. Also,
similarly to the first embodiment, the wound portion 2a and the
inner core portion 31a will be described as examples.
[0160] As shown in FIG. 4B, in the reactor of the second
embodiment, the axis Q has been shifted downward and to the side
(inner side) at which the wound portions 2a and 2b are close to
each other, from the state in which the axis P of the wound portion
2a and the axis Q of the inner core portion 31a are coaxial. In
this state, the interval between the wound portion 2a and the inner
core portion 31a differs in the peripheral direction of the wound
portion 2a. The interval g.sub.ue of the corner portions on the
upper side of the interval between the wound portion 2a and the
inner core portion 31a is the largest. The interval g.sub.i on the
inner side, the interval of the corner portion on the inner side
and lower side, and the interval g.sub.d on the installation target
100 side (lower side) are the smallest (g.sub.i=g.sub.d=t1). The
interval g.sub.u on the upper side and the interval g.sub.o on the
side (outer side) at which the wound portions 2a and 2b are spaced
apart from each other are equal to each other, and are greater than
70% of the maximum value (=interval g.sub.ue=t2) of the interval.
The interval of the location that is 70% of the maximum value of
the interval among the corner portions on the outer side and the
lower side is the interval g.sub.de. If the location that satisfies
the condition of being 70% or less of the maximum value of the
interval is the relatively narrow location, the relatively narrow
location has an L shape. The electrically insulating material 7 and
a portion (thin portion 610) of the inner resin portion 61 are
present at the relatively narrow location (FIG. 4A). Also, if the
location that satisfies the condition of being greater than 70% of
the maximum value of the interval is the relatively wide location,
the relatively wide location has an inverted L shape. The thick
portion 612 is present at the relatively wide location (FIG.
4A).
[0161] In the present example, the intervals g.sub.d and g.sub.i,
which are the minimum values of the interval, are 5% or more and
25% or less of the interval g.sub.ue, which is the maximum value of
the interval, and are smaller than in the first embodiment. In this
respect, the interval t1 is easily made much smaller than the
interval t2. The electrically insulating material 7 is present at
the narrowest location. A thin object such as insulating paper or
insulating film can be suitably used as the electrically insulating
material 7 of the present embodiment. Even if the electrically
insulating material 7 is the insulating paper, the insulating film,
or the like and the thermal conductivity .lamda.1 is made greater
than the thermal conductivity .lamda.2 of the thick portion 612,
the interval t1 is much smaller than the interval t2 as described
above. Because of this, the reactor of the second embodiment
satisfies (interval t1/thermal conductivity .lamda.1)<(interval
t2/thermal conductivity .lamda.2).
[0162] Also, in the present example, the length percentage of the
location at which the interval is relatively narrow with respect to
the inner peripheral length of the one wound portion 2a is 40% or
more and 60% or less, and is smaller than in the first embodiment.
Accordingly, it can be said that the reactor of the present example
includes more locations at which the interval is relatively wide
than in the first embodiment. Also, the minimum value of the
interval is smaller than that of the first embodiment as described
above. For this reason, the reactor of the second embodiment easily
ensures a larger maximum value (=interval g.sub.ue=t2) of the
interval compared to the first embodiment.
[0163] Furthermore, in the present example, percentage of the area
occupied by the electrically insulating material 7 with respect to
the location at which the interval is relatively narrow in the one
wound portion 2a is 60% or more and 80% or less, and is greater
than in the first embodiment. Accordingly, it can be said that the
reactor of the present example includes more electrically
insulating materials 7 at the location at which the interval is the
narrowest, compared to the first embodiment.
[0164] The reactor of the second embodiment has an excellent heat
dissipation property due to reasons similar to those of the first
embodiment. In particular, an excellent heat dissipation property
is achieved due to the fact that the interval t1 is likely to be
much smaller than the interval t2. With the reactor of the present
example, an excellent heat dissipation property is achieved also
due to the fact that the occupation percentage of the location at
which the electrically insulating material 7 is present, that is,
the location of the interval t1, is greater than that of the first
embodiment (see the above-described percentage of area). Also, the
reactor of the present example has an excellent heat dissipation
property due to the fact that the location at which the interval is
relatively narrow includes a flat plate-shaped location similarly
to the first embodiment.
[0165] Furthermore, in the reactor of the present example, the
relatively wide location is larger than that of the first
embodiment as described above. For this reason, in the
manufacturing process, filling with the fluid resin is more easily
performed. Due to the resin molded portion including the inner
resin portion 6 being easy to manufacture, the reactor of the
second embodiment has a more excellent manufacturability. Filling
with the fluid resin is easily performed also due to the fact that
the relatively wide location is provided toward the upper sides and
the outer sides of the wound portions 2a and 2b and the inner core
portions 31a and 31b.
[0166] Furthermore, the reactor of the present example has
excellent rigidity as an integrated object of the magnetic core
resulting from being held in the resin molded portion. This is
because the thick portions 612 are provided relatively on the upper
sides and outer sides of the inner core portions 31a and 31b. Here,
the lower sides of the inner core portions 31a and 31b are
protected by the installation target 100. The inner sides of the
inner core portions 31a and 31b that are adjacent to each other are
protected due to the wound portions 2a and 2b being interposed. In
contrast to this, it can be said that the upper sides and outer
sides of the inner core portions 31a and 31b are likely to receive
an impact or the like from the exterior. The reactor of the present
example can effectively reinforce the upper sides and the outer
sides of the inner core portions 31a and 31b using the thick
portions 612.
[0167] In addition, due to including the insulating paper or the
like at the location at which the interval is the narrowest, the
reactor of the present example also has excellent electrical
insulation between the wound portions 2a and 2b and the inner core
portions 31a and 31b compared to the case of including air.
Third Embodiment
[0168] A reactor of a third embodiment will be described with
reference to FIG. 5.
[0169] As shown in FIG. 5, the basic configuration of the reactor
of the third embodiment is similar to that of the reactor 1 (see
FIG. 2A) of the first embodiment. That is, the interval between the
wound portion 2a and the inner core portion 31a and the interval
between the wound portion 2b and the inner core portion 31b differ
in the peripheral directions of the wound portions 2a and 2b. The
inner resin portions 61 that include the thin portions 610 and the
thick portions 612 are present between the wound portions 2a and 2b
and the inner core portions 31a and 31b. However, the reactor of
the third embodiment differs from the reactor 1 of the first
embodiment in that it does not include the electrically insulating
materials 7 that are independent of the resin molded portions 6.
Hereinafter, the differences will mainly be described, and detailed
description of configurations and effects that are redundant with
those of the first embodiment will be omitted.
[0170] In the reactor of the third embodiment, the inner resin
portions 61 are formed into tube shapes continuously in the axial
directions of the wound portions 2a and 2b. The constituent resin
of the inner resin portion 61 fills the entirety of the location at
which the interval is relatively narrow, and the thin portions 610
are present therein. Portions of the thin portions 610 form the
electrically insulating materials 7. Accordingly, the thermal
conductivity .lamda.1 of the electrically insulating materials 7 is
substantially the same as the thermal conductivity .lamda.2 of the
thick portions 612 (.lamda.1=.lamda.2). The predetermined interval
t1 in which the electrically insulating material 7 is arranged is
smaller than the predetermined interval t2 in which the thick
portion 612 is arranged (t1<t2). For this reason, the reactor of
the third embodiment satisfies (interval t1/thermal conductivity
.lamda.1)<(interval t2/thermal conductivity .lamda.2) and has an
excellent heat dissipation property.
[0171] The reactor of the third embodiment has excellent
manufacturability in that the electrically insulating material 7
that is independent of the resin molded portion 6 is not needed and
the number of assembly steps can be reduced. Also, only the inner
resin portions 61 composed of materials with uniform thermal
expansion coefficients are present between the wound portions 2a
and 2b and the inner core portions 31a and 31b. For this reason,
the reactor of the third embodiment also has excellent strength in
that cracking and the like of the inner resin portion 61 caused by
a difference in the thermal expansion coefficient are not likely to
occur.
[0172] The present disclosure is not limited to these examples but
is indicated by the claims, and all modifications that fall within
the meaning and range of equivalency with the claims are intended
to be encompassed therein.
[0173] For example, at least one of the following modifications is
possible in the above-described first to third embodiments.
Modified Example 1
[0174] The electrically insulating material includes air.
[0175] In this case, from the viewpoint of ensuring electric
insulation between the wound portion and the inner core portion, it
is preferable that electric insulation is sufficiently ensured by
the coil, as described above.
Modified Example 2
[0176] Multiple electrically insulating materials (molded bodies)
are arranged in one wound portion.
[0177] In this case, specifications such as the shape, size, and
constituent material of the electrically insulating material can
also all be made equal, or can all be made different. For example,
one wound portion may also include the insulating paper and the
resin molded body. If the multiple electrically insulating
materials are included spaced apart from each other in the
peripheral direction of the wound portion, the inner resin portions
may also be interposed between the adjacent electrically insulating
materials. Air may also be present between the adjacent
electrically insulating materials without the inner resin portions
being interposed therebetween. In this case, there is no need to
fill the narrowest location with the fluid resin as described
above, and the resin molded portion is easily formed.
Modified Example 3
[0178] The location at which the interval is the narrowest is
provided at a position other than the installation target.
[0179] Description will be given with reference to FIG. 2A. The
location at which the interval is the narrowest may also be
provided between the surfaces (upper surfaces) of the inner
peripheral surfaces of the wound portions 2a and 2b on the side
opposite to the installation target 100 and the upper surfaces of
the inner core portions 31a and 31b. Alternatively, the location at
which the interval is the narrowest may also be provided between
the side surfaces (the right surface in the wound portion 2a and
the left surface in the wound portion 2b) on the sides of the inner
peripheral surfaces of the wound portions 2a and 2b that are spaced
apart from each other and the side surfaces of the inner core
portions 31a and 31b. In this case, the cooling mechanism may be
arranged close to the upper surfaces of the outer peripheral
surfaces of the wound portions 2a and 2b and the above-described
side surfaces.
Modified Example 4
[0180] The outer peripheral shape of the inner core portion is not
analogous to the inner peripheral shape of the wound portion.
[0181] In this case, the interval between the wound portion and the
inner core portion can be changed according to the inner peripheral
shape of the wound portion and the outer peripheral shape of the
inner core portion. It is preferable that the shape and the size of
the wound portion and the inner core portion are adjusted such that
the interval is a predetermined size. For example, if the inner
peripheral shape of the wound portion is the square shape described
in the first to third embodiments, the outer peripheral shape of
the inner core portion may be a circular shape, a trapezoidal
shape, or the like. Alternatively, the inner peripheral shape of
the wound portion and the outer peripheral shape of the inner core
portion may be rectangular and have different ratios between their
long side lengths and their short side lengths.
Modified Example 5
[0182] The inner core portion is a set composed of multiple core
pieces and multiple gap materials (may also be air gaps) (see JP
2017-135334A).
[0183] The set composed of the multiple core pieces and a solid gap
material may be integrated using an adhesive, or may be integrated
using the inner resin portion 61 of the resin molded portion 6.
Modified Example 6
[0184] The reactor includes at least one of the following (none are
shown in the drawings).
[0185] A sensor that measures a physical amount of the reactor,
such as a temperature sensor, a current sensor, a voltage sensor,
or a magnetic flux sensor.
[0186] A heat dissipation plate that is attached to at least a
portion of the outer peripheral surfaces of the wound portions 2a
and 2b of the coil 2.
[0187] Examples of the heat dissipation plate include a metal plate
and a plate material composed of a non-metal inorganic material
with an excellent thermal conductivity. If the heat dissipation
plate is provided at a location of the outer peripheral surfaces of
the wound portions 2a and 2b that corresponds to the location at
which the interval is relatively narrow, heat can be dissipated
efficiently. To give a description with reference to FIGS. 2A and
4A, the heat dissipation plate may be provided on the surfaces
(lower surfaces) of the outer peripheral surfaces of the wound
portions 2a and 2b on the installation target side. In FIGS. 2A and
4A, the surfaces on the installation target 100 side of the wound
portions 2a and 2b are positions that correspond to the locations
at which the interval is the narrowest, and the electrically
insulating material 7 is present thereon. In addition, the heat
dissipation plates may also be arranged on the right surface of the
outer peripheral surface of the wound portion 2a and the left
surface of the outer peripheral surface of the wound portion 2b.
Alternatively, the heat dissipation plates may also be provided at
the locations at which the thick portions 612 are present. It is
expected that this reactor can, to some extent, improve the drawing
of heat from the inner core portions 31a and 31b to the wound
portions 2a and 2b via the thick portions 612 using the heat
dissipation plates.
[0188] A bonding layer that is interposed between the installation
surface of the reactor 1 and the installation target 100, or
between the installation surface and the above-described heat
dissipation plate.
[0189] Examples of the bonding layer include an adhesive layer. If
an adhesive layer with excellent electric insulation is used, even
if the heat dissipation plate is a metal plate, the insulation
between the wound portions 2a and 2b and the heat dissipation plate
is improved, which is preferable.
[0190] An attachment portion that is molded in one piece with the
outer resin portion 62 and is for fixing the reactor 1 to the
installation target 100.
* * * * *